Optical computing, which is based on beam propagation properties of mutually noninteracting photons, has the potential of performing information processing several orders of magnitude greater than its electronic counterpart. However, to fulfill this expectation, nonlinear optical devices must be developed that perform logical operations on either optical or electrical input information and output the processed information optically or electrically. In particular, these optical devices must be compact, consume small power, exhibit large optical gain, and, importantly, must be integratable in order to achieve high density.
A solid state device, termed a DOES (which is an acronym for a Double Heterostructure Opto-Electronic Switch) has recently been developed by one of the inventors which potentially can satisfy all of the above criterion. See U.S. Pat. No. 4,806,997 which is incorporated herein by reference. Specifically, the DOES, which is based upon an induced inversion layer at a heterojunction interface, is an electrically and optically bistable device which may be switched between states by either an electrical or optical input. In a first state, the device has a high electrical impedance and emits no light, while in a second state, the device has a low impedance and strongly emits optical radiation.
The initial implementation of the DOES was in a surface emitting light-emitting diode (LED) form. While the abovementioned device is advantageous in that its unique electrical and optical characteristics make it extremely attractive for digital optical operations, it would be further desirable to improve the power conversion efficiency as well as the beam collimation thereof.